This invention relates to a passive seat belt system for vehicles which automatically fastens and unfastens the seat belt in accordance with wearer's intentional movement of getting in and out.
Conventionally, the seat belt is fastened and unfastened manuallly. However, because of the troublesomeness, such as seat belt system has not been always used, resulting in poor protection of unbelted occupants. To cope therewith, it has been proposed to fasten and unfasten the seat belt automatically. However, such a system also provides an obstacle for the free entry and exit of the occupants, because of its many complex parts, such as rails, hangers, limit switches and so on, which result in high cost and poor reliability.